Final (Part 3)

Question 1

3 mechanisms of speciation?

Answer 1

Ecological, Polyploidization, Reinforcement

Question 2

end point of taxa?

Answer 2

reaches irreversible endpoint when two taxa cannot form fertile hybrids, seperate gene pools between alleles cannot move

Question 3

what is a biological species

Answer 3

groups that actually or potentially interbreed and produce fertile offspring, and dont form offspring with members of other groups

Question 4

what is speciation

Answer 4

process by which one species splits into two or more species

Question 5

what are the results of experimental evolution

Answer 5

predicts stronger behavioural isolation between populations adapted to different environments compared to populations adapted to same
environment

Question 6

geography of speciation?

Answer 6

Sympatric vs. allopatric are two extremes in a gradient of gene flow between diverging populations

Question 7

dis/advantages of BSC

Answer 7

Provides a straightforward approach to studying speciation
*Can’t be applied to asexual taxa (e.g., prokaryotes) or fossils
*Can be hard to assay reproductive barriers

Question 8

prezygotic barriers?

Answer 8

Lower likelihood of success when mating- habitat isolation, temporal isolation, behavioral/pollinator isolation, mechanical isolation or gametic isolation

Question 9

postzygotic barriers?

Answer 9

reduce survival of hybrid- genetic incompatibilites, ecologically-dependent postzygotic isolation (fall between niches),

Question 10

what is polyploidization

Answer 10

increase in the # of whole sets of chromosomes (i.e., 2n, 3n, 4n, etc.)
postzygotic can be instantaneous
occurs in sympatry, common in ferns & flowering plants

Question 11

what is BSC

Answer 11

biological species concept

Question 12

new daughter species…

Answer 12

share characteristics because they are descended from common ancestor, related to one another through varying degrees

Question 13

how to study speciation in nature?

Answer 13

Hybrids struggle in mismatched environments due to their traits. Ecological differences drive distinct traits in species, tested by transplant experiments.

Question 14

Ecological SC

Answer 14

defines species based on their ecological niche; i.e., groups that inhabit thesame niche

Question 15

is sympatric speciation common?

Answer 15

Evidence suggests sympatric speciation is extremely rare

Question 16

what is ecological speciation?

Answer 16

reproductive isolation arises as a by-product of adaptation to different environments or niches
* can occur under any geographic context

Question 17

experimental evolution?

Answer 17

technique in which multiple, replicate populations
are derived from a common ancestor and then their evolution is tracked under conditions that the experimenter controls

Question 18

what is reinforcement

Answer 18

The strengthening of prezygotic barrier by natural selection in response to reduced
hybrid fitness
Can complete a speciation event initiated by any mechanism, Requires contact

Question 19

Morphological SC

Answer 19

defines species based on morphological similarity

Question 20

2 ways to study speciation

Answer 20

labratory studies, speciation in nature

Question 21

example of ecological speciation

Answer 21

Darwin finches, adapting different beaks to different food sources on various islands

Question 22

what is reproductive isolation

Answer 22

opposite of compatability, result of reproductive barriers

Question 23

2 types of polyploidization

Answer 23

autopolyploid - an individual with more than two
chromosome sets derived from a single species
allopolyploid - an individual with more than two
chromosome sets derived from different species

Question 24

allopatric vs sympatric geography

Answer 24

Allopatric – occurring in separate, non-overlapping geographic areas
Sympatric – occurring in the same, overlapping geographic area

Question 25

example of reinforcement

Answer 25

closely related butterfly species occasionally interbreed, natural selection favors distinct traits such as unique colors or behaviors that reduce successful mating between them